Recipient Of Pig Kidney Transplant Leaves The Hospital

12:16 minutes

Four people wearing masks stand around a man in a chair, all looking happily at the camera. They're in a hospital room.
Patient Rick Slayman getting ready to leave Massachusetts General Hospital after his kidney transplant. Credit: Michelle Rose/Massachusetts General Hospital

Last month, Massachusetts General Hospital in Boston announced that a team of doctors had transplanted a kidney from a genetically engineered pig into a living human for the first time. This week, that patient, a 62-year-old man living with end-stage kidney disease, was sent home from the hospital, having recovered enough to be discharged. Sixty-nine genes were edited in the donor pig, including three that coded for a certain sugar found on the surface of pig cells. The edits, hopefully, will make it less likely for the human recipient to reject the transplant.

Umair Irfan, senior correspondent at Vox, joins Ira Flatow to talk about the xenotransplantation advance, and how it could affect patients awaiting donor organs. They’ll also talk about other stories from the week in science, including how power grid operators are preparing for the upcoming solar eclipse, NASA’s search for a new lunar rover, an advance in getting robots to make appropriate faces, research into using a drug similar to the obesity medication Ozempic to delay Parkinson’s symptoms, and plans for a new time zone—on the moon.

Further Reading

Segment Guests

Umair Irfan

Umair Irfan is a senior correspondent at Vox, based in Washington, D.C.

Segment Transcript

IRA FLATOW: This is Science Friday, I’m Ira Flatow. Later in the hour, your guide to Monday’s solar eclipse. Plus, how AI might help to diagnose heart disease. But first, last month, researchers announced that a gene-modified pig kidney had been transplanted into a person. This week, the recipient of that kidney was discharged from the hospital and sent home. Here to tell us more is Umair Irfan, senior correspondent at Vox in Washington, DC. Welcome back, Umair.

UMAIR IRFAN: Hey, Ira. Thanks for having me back.

IRA FLATOW: Rewind the clock a bit. What happened here?

UMAIR IRFAN: Well, as you noted, there was a patient that received a genetically-modified pig kidney last month. The patient’s name is Rick Slayman. He’s 62 years old and he was suffering from end-stage renal disease. And now, it turns out that he got well enough that he could actually go home.

This is actually a huge step forward because we’ve been able to do some kinds of pig-to-human xenotransplants, as they’re called, for some time, but they’ve been very high-risk procedures. There was previously a kidney transplanted into a brain-dead patient, but this patient, Rick Slayman, is very clearly alive, and it shows that this kidney was actually functioning normally enough that it could actually replicate human kidney function.

IRA FLATOW: Now this was not just a plain kidney. They had to genetically engineer this pig, right?

UMAIR IRFAN: Yeah. They had to make a couple changes to these kidneys to, one, to get rid of the pig proteins or some of the markers on the kidney that would trigger an immune response, but also to add human markers on the kidney that would make it more easily and readily accepted because when you have an organ transplant, one of the biggest risks and one of the challenges is rejection, that the host can not integrate that organ or that the immune system can turn against it.

People who receive organ transplants often are on immunosuppressant drugs the rest of their lives, and that can lead to a whole bunch of other problems. And so if you can smooth that transition, you can also improve the prognosis for patients who get these transplants.

IRA FLATOW: So this might be one of many and it might Herald an era of other organs beyond kidneys.

UMAIR IRFAN: Right. We’ve seen already a heart transplant, but the issue here is that the demand for kidney transplants is so immense in the United States. There’s about 135,000 people each year who are diagnosed with end-stage renal disease, but only about 25,000 transplants take place.

And my colleague, Dylan Matthews, just wrote an article just arguing that we also need to be doing a lot more to be increasing donations using our conventional methods. And so that’s from living donors, because we have two kidneys, you can live with one, and also encouraging more people to be organ donors after they die. And we can actually meet the supply if we were to encourage more people to get on the donor registries and take more aggressive steps to fill this need.

IRA FLATOW: Interesting. Let’s move on to some other interesting medical news. You have a story about work with Moderna’s mRNA vaccine technology, but not as a vaccine, but to treat a disease. Tell us about that

UMAIR IRFAN: Right. Actually, you may know that Moderna, before they developed the COVID-19 vaccine, were initially developing mRNA as a treatment for diseases. You may recall with the mRNA technology, what it does is it uses a little piece of genetic code that teaches the body to make a component of a virus.

And in this case, rather than making a piece of a virus, what they did was that they used it to teach the body to make an enzyme for people who are suffering from this disease called propionic acidemia. And so when that enzyme is defective, it causes toxins to build up in organs in the body and it can cause all sorts of problems there.

And so they reasoned that if we could coach the body to make this enzyme on their own rather than treating it with drugs, the patients could actually improve their health outcomes. And so one of the things that they found was when they treated patients with this, that their risk of emergencies dropped dramatically, and some of these patients were able to take this treatment for up to two years. So it shows that this could actually be a viable therapy that could actually help treat other kinds of illnesses.

IRA FLATOW: Would those illnesses possibly include cancer, cancerous tumors, things like that?

UMAIR IRFAN: Yeah, exactly. So one of the other goals they want to use with this mRNA technology is to target tumors. Basically, if you can get the mRNA into tumor cells, the mRNA can actually paint targets on them to actually coach the body’s immune system to target them, and this could potentially be another way to target cancer going forward.

IRA FLATOW: Terrific, terrific. Staying on the medical front for one more story, there’s been a lot of attention given to drugs like Ozempic for weight loss, but there’s news this week about using a related drug to slow the progress of Parkinson’s disease.

UMAIR IRFAN: Yeah, that’s right. So Ozempic falls into this category of drugs called GLP-1, and there’s another related drug called lixisenatide that was used in this French study in patients who have Parkinson’s disease. You know this is the illness that causes tremors and stiffness and difficulty with balance and dementia. It’s a very dangerous progressive illness and doesn’t really have a whole lot of treatment.

But they found that when they used this drug in some of the patients, they saw improvements in some of those symptoms– having less tremors, fewer stiffness, and better cognitive outcomes. And it signals that even though this is a neurological disease, there’s probably some sort of digestive system mechanism that’s associated with it as well.

IRA FLATOW: Do we know why this type of drug seems to be effective against so many different kinds of conditions? I mean, you just pointed to that. Could that be the key here?

UMAIR IRFAN: Well, there’s a lot of different mechanisms likely at work. The GLP-1 drugs mimic a hormone that’s produced by the intestines, and that causes your body to produce more insulin, it makes your stomach feel more full, and that can have downstream effects in other organ systems. But it also appears that GLP-1 drugs can also attach to neurons.

And so that means that they can also have some direct effects in our brains as well that we don’t maybe fully appreciate. And so scientists are hoping to learn a little bit more about these mechanisms and hopefully develop more targeted ways to improve outcomes in people with these kinds of degenerative illnesses.

IRA FLATOW: I love it when we find stuff we never knew about before. OK, we’re all excited about the eclipse on Monday, and later in this hour, we have our eclipse preview, but you have a story out today about how the power grid operators are preparing. And I don’t mean by stockpiling eclipse glasses. What’s it have to do with the power grid?

UMAIR IRFAN: Well, as you may note that we’ve seen a big boom in renewable energy in recent years, and particularly solar power. So when the moon passes in front of the sun, that’s going to have some pretty significant impacts on the power grid. In the United States, since the last eclipse in 2017, we’ve had nearly 2 and 1/2 times as much solar power on the grid, and one of the biggest states that has some of the most solar power in the country is Texas.

And if you look at the map of the eclipse, that’s passing straight through the Lone Star State. And so grid operators there are preparing for a significant drop-off in solar energy, as well as a very significant ramp-up when that power comes right back.

And so right now, they’re taking steps and doing modeling to try to make sure that they have enough power, but this is also a useful case study because we’re expecting even more renewable energy to be coming onto the grid in coming years. And with more intermittency on the grid, grid operators have to actually do a lot more planning to make sure that when there are things like cloudy days or other kinds of shortfalls in power, that they have enough electricity to balance the demand and the supply to keep everything flowing smoothly.

IRA FLATOW: Yeah, that’s a question I was going to ask about that. I mean, solar operators already have to deal with cloudy days and night times, so why is this eclipse different?

UMAIR IRFAN: Well, the eclipse is different because it’s happening so quickly. So we normally see a ramp-up when the sun rises and a ramp-down when the sun sets, but we’re talking now a huge drop-off on the order of minutes. So we’re talking about nearly a 60-gigawatt drop of power across the US power grid in a few minutes and then suddenly having to replace that.

And that’s not trivial for the power grid. While we see more energy storage on the grid, there isn’t enough to make up that entire shortfall, so you need other generators that are ready to quickly ramp back up and ramp back down, and if you don’t do it right, we could see either blackouts if you don’t have enough power or we could see instability if you have too much power. It’s a delicate balancing act. And having something this acute this fast is a really difficult challenge.

IRA FLATOW: All right, let’s talk about another technology advance, and I’m talking about this one is in the important field of getting robots to make funny faces. What’s significant here?

UMAIR IRFAN: Right. So a team of scientists, they built this anthropomorphic robot called EMO. And it has 26 motors underneath this flexible blue silicone face to give it precise controls about how it mimics and imitates emotions. The critical thing here, though, is that what the scientists did is that they taught this robot across a large data set on what human emotions look like. And critically, what they’re trying to teach it to do is not just mimic what it sees a person do, but anticipate emotions. And so they’re trying to teach this to be empathetic in terms of how it expresses.

So when you smile, it smiles or it can respond within milliseconds to maybe show a frown. And so the idea is we want to be able to have this anticipate how somebody is talking and how a robot should maybe react to it, but obviously you don’t want to send the wrong signals. You don’t want to be smiling when somebody is telling you a sad story, you don’t want to be frowning when somebody is trying to tell you something exciting. And so there’s this sort of delicate balancing act here as well about how we get these machines to mimic human emotions.

IRA FLATOW: Let’s talk about buying a new car, Umair. I mean, many of us have had that experience. You consider different models and such. You go for a test drive or so. But NASA is on the market for a new lunar rover. You’re not going to test drive that on the moon. How do you shop for one of those?

UMAIR IRFAN: Well, NASA recruited its new big three for the moon– not General Motors, Stellantis, and Ford, but these three companies called Intuitive Machines, Lunar Outpost, and Venturi Astrolab. They are going to be private contractors that are going to be submitting candidates for a vehicle to drive on the moon that’s going to be launched with the Artemis mission and potentially future private space missions as well.

NASA previously has put vehicles on the moon, but they were designed in-house, and what they’re saying is with this competitive process with the private companies, they can hopefully get better or cheaper vehicles, but also approach new designs that can help astronauts get around the moon the next time they’re there.

IRA FLATOW: Any way to get these, these models to the moon to test-drive them?

UMAIR IRFAN: Not just yet. NASA has its own testing facilities here in the United States, but they will eventually have to go through some pretty tough challenges. Pneumatic tires, for instance, don’t work the same way on the moon because there’s no air pressure, and so you have to design the tires very differently. And they also have to be very compact and lightweight enough to be launched up on a rocket. So there’s a lot of constraints you face on the moon that you don’t face on your normal streets. And so–


UMAIR IRFAN: Whether or not they have cup holders and radio and all these other kinds of features, I don’t know that NASA’s going to spring for those, but certainly they will be looking for some really important features that we haven’t experienced before, including self-driving, which is–

IRA FLATOW: Self-driving. Yeah. There’s also news on the lunar beat there’s a call for a lunar time zone.

UMAIR IRFAN: Well, yes, now that we have so many more companies and governments trying to land on the moon, we need to coordinate and get everybody on the same clock. If you call your lunar self-driving taxi on the moon, if it shows up at the wrong time, you know you’re not going to be there.

And so the problem on the moon is that time actually moves a little bit quicker there relative to the Earth, about 58.7 microseconds every day. And that’s actually enough to throw off spacecraft and time instruments. And so the White House recently asked NASA to develop what they called a coordinated lunar time. But they also have to work with other countries– obviously this is an international effort. We’ve already established space time zones on the International Space Station, so this will be another coordinated effort to get the whole world on board with the standard for further space exploration.

IRA FLATOW: Umair, it’s always a good time when you’re around. Thanks for joining us this week again.

UMAIR IRFAN: My pleasure, Ira. Thank you for having me.

IRA FLATOW: One quick note. On last week’s News Roundup, we featured a story about how climate change may actually be changing the way we keep time, pushing back the need for a leap second to reconcile atomic clocks with the Earth’s rotation. And our reporter said that’s because the Earth’s rotation is speeding up. But according to the paper in Nature we were citing, the Earth’s rotation is actually slowing down, and we regret the error.

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